Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Gul, Muhammet(102)
- Güler, Ömer(69)
- Akkurt, Nevzat(68)
- Tekin, H.O.(52)
- ALMisned, Ghada(49)
- Yucesan, Melih(49)
- Celik, Erkan(45)
- Zengin, Gokhan(40)
- Serdar, Osman(39)
- Kocabaş, Mehmet(37)
- Aslan, Naim(31)
- Baskonus, Haci Mehmet(31)
- Bulut, Hasan(31)
- Mete, Suleyman(31)
- Paksoy, Mehmet Yavuz(30)
- Kök, Mediha(27)
- Ince, Muharrem(26)
- Yildirim, Ozal(26)
- Özkul, İskender(26)
- Sulaiman, Tukur Abdulkadir(25)
- Topal, Murat(25)
- Guler, Omer(24)
- Serin, Faruk(23)
- Benzer, Fulya(22)
- Erten, Fusun(22)
- Alataş, Mevlüt(21)
- Güler, Seval Hale(21)
- Baykal, Duygu Sen(20)
- Taşgın, Yahya(20)
- Kutlu, Banu(19)
- Onat, Onur(19)
- Sahin, Kazim(19)
- Tanyol, Mehtap(19)
- Torğut, Gülben(19)
- Yildirim, Numan(19)
- Kahraman, Gökhan(18)
- Orhan, Cemal(18)
- Say, Yakup(18)
- Susam, Selim Orhun(18)
- Utku, Anıl(18)
Yayınlar
- MakaleAçık Erişim2017Scopus SJRQ3The effect of harvest time on the bioactive properties and volatile components of lavender (Lavandula officinalis)
Yalcin, H.; Kavuncuoğlu, H.; Tulukcu, E.; Eroğlu, Z.
This study was designed to determine the effect of harvest time on the bioactive properties and volatile components of flowers, leaves and stems of Lavandula officinalis. The bioactive properties were examined in terms of total phenolic content, antiradical activity and antioxidant capacity by the Folin-Ciocalteu, 1.1-diphenyl-2-picrylhydrazyl scavenging and phosphomolybdenum methods, respectively. Volatile components were detected with gas chromatography-mass spectrometry. Water and methanol were used for extraction solvent and three different parts of the day (morning, midday and evening) were selected for harvest time. Water extracts had higher total phenolic contents (337.2-771.5 mg gallic acid equivalents (GAE)/g dry extract) than methanolic extracts (170.3-320.8 mg GAE/g dry extract), and in general, midday values were less than morning and evening rates and had a significant difference depending on harvest time. A similar feature was observed in respect to antioxidant properties. The inhibition rates (%) of flowers and leaves were higher than those of the stems for either extract. In terms of the volatile components linalool, camphor, 1,8-cineole, terpinen-4-ol and isoborneol were the most representative compounds in the samples.
AtıfScopus10WoS10OpenAlex9
İncele - BildiriYalnız künye2017An ann and ga approach for demand forecasting and routing for cash management
Gumus, Alev Taskin; Celik, Erkan; Ömerustaoğlu, Furkan; Drobne, S.; Zerovnik, J.; Zadnik Stirn, L.; Kljajic Borstar, M.
Forecasting of cash demand and cash transportation are critical processes for all bank asynchronous transfer modes (ATMs). In this paper, an application is presented to accurate forecasting of cash demand and minimizing the transportation cost. In the first step of the proposed application, artificial neural network is implemented for forecasting the amount of withdrawn and deposited money from an ATM in one day. Hence, a more accurate way is provided to determine the amount of money that will be loaded into the ATM, and opportunity costs are minimized. Then, we applied genetic algorithm for minimizing the transportation cost of cash deposit to the ATMs.
- MakaleYalnız künye2017Scopus SJRQ1An integral based fuzzy approach to evaluate waste materials for concrete
Onat, Onur; Celik, Erkan
Waste materials in concrete have been considered as one of the most important issues by the authorities, policy makers and researchers to maintain engineering serviceability in terms of economy, durability and sustainability. Therefore, evaluation and selection of waste materials with respect to multi criteria decision making (MCDM) for the construction industry has been gained importance for recovery and reuse. In this paper, Choquet integral based fuzzy approach is proposed for evaluating the most suitable waste materials with respect to compressive strength, tensile strength, flexural strength, compactness, toughness (resistivity for dynamic loads), water absorption and accessibility. On conclusion, waste tyre and silica fume were determined as the most suitable waste materials for concrete production. The obtained results are recommended to assist the authorities on configuring well designed strategies for construction industry with disposal materials.
AtıfScopus12WoS12OpenAlex9İncele - MakaleYalnız künye2017Scopus SJRQ1Biodegradation of hydroxyapatite coated Rex-734 alloy with silver and selenium/chitosan substitutions: In vitro analysis
Aksakal, B.; Say, Y.; Buyukpinar, Ç.; Bakirdere, S.
Hydroxyapatite (HA) based bioceramic coatings; such as single-HA, double layered with Silver-Ag, Selenium-Se and Chitosan substitutions on Rex-734 alloy were executed by using the sol-gel method. Surface morphologies and adhesion strengths of the obtained coatings were investigated and coating material weight losses and metal ion releases from the substrates were determined in SBF (Simulated Body Fluid) environment. The coatings were characterized by SEM, EDS, XRD and adhesion strengths between the substrate and bioceramic coatings were measured with adhesion tests. SEM analyses revealed that crack-free surface morphologies were obtained in all bioceramic coatings. The coatings were kept in SBF for immersion periods from one to four weeks and the weight loss (%) in coatings and changes in ion release rates were determined. HA/Ag double layered coatings applied on the Rex-734 alloy increased the adhesion strength and accordingly reduced the weight losses (%) of coating materials in SBF. Se/Chitosan double layered coatings were found to decrease the adhesion strength and increase the weight losses (%) in SBF. Additionally, all bioceramic coatings were observed to prevent the elemental ion release by physical barrier effect for the release of metal ions during the four weeks immersion period in SBF.
AtıfScopus12WoS11OpenAlex12İncele - MakaleYalnız künye2017Scopus SJRQ1PIV measurements in the near wakes of hollow cylinders with holes
Firat, Erhan; Ozkan, Gokturk M.; Akilli, Huseyin
The wake flows behind fixed, hollow, rigid circular cylinders with two rows of holes connecting the front and rear stagnation lines were investigated using particle image velocimetry (PIV) for various combinations of three hole diameters, d = 0.1D, 0.15D, and 0.20D, six hole-to-hole distances, l = 2d, 3d, 4d, 5d, 6d, and 7d, and ten angles of incidence (α), from 0° to 45° in steps of 5°, at a Reynolds number of Re = 6,900. Time-averaged velocity distributions, instantaneous and time-averaged vorticity patterns, time-averaged streamline topology, and hot spots of turbulent kinetic energy occurred through the interaction of shear layers from the models were presented to show how the wake flow was modified by the presence of the self-issuing jets with various momentums emanating from the downstream holes. In general, as hole diameter which is directly related to jet momentum increased, the values of time-averaged wake characteristics (length of time-averaged recirculation region, vortex formation length, length of shear layers, and gap between the shear layers) increased. Irrespective to d and l tested, the values of the vortex formation length of the models are greater than that of the cylinder without hole (reference model). That is, vortex formation process was shifted downstream by aid of jets. It was found that time-averaged wake characteristics were very sensitive to α. As α increased, the variation of these characteristics can be modeled by exponential decay functions. The effect of l on the three-dimensional vortex shedding patterns in the near wake of the models was also discussed.
AtıfScopus26WoS25OpenAlex28İncele - MakaleAçık Erişim2017Scopus SJRQ1Application of response surface methodology for optimization of Remazol Brilliant Blue R removal onto a novel polymeric adsorbent
Torgut, Gulben; Tanyol, Mehtap; Biryan, Fatih; Pihtili, Guzin; Demirelli, Kadir
The poly[2-hydroxy-3-(1-naphthyloxy)propyl] methacrylate [poly(NOPMA)] was used as a novel adsorbent for the removal of Remazol Brilliant Blue R (RBBR) known as a reactive dye. Physico-chemical properties of polymer were analyzed by FT-IR and SEM before and after dye adsorption. The Langmuir and Freundlich isotherms were used to explain the adsorption equilibrium, and when it was compared with each other it was seen that the adsorption process was well explained by the Langmuir isotherm model and showing a monolayer adsorption capacity for RBBR of 238.10 mg/g. Kinetic models known as pseudo-first-order, pseudo-second-order and intra-particle diffusion model were utilized to analyze the mechanism of adsorption, and results indicated that was an adsorption kinetic suitable with the pseudo-second-order. The thermodynamic parameters (∆Ho, ∆So, ∆Go) indicated that the adsorption process was spontaneous and endothermic. To optimize the study conditions, the effects of the concentration of RBBR, adsorbent amount and contact time on the adsorption were investigated by response surface methodology (RSM). According to RSM results, maximum RBBR removal was reached at the optimum initial dye concentration of 60.85 mg/L, adsorbent dosage of 0.04 g/50 mL and contact time of 59.91 min.
AtıfScopus40WoS37OpenAlex43İncele - MakaleYalnız künye2017Scopus SJRQ1Reduction of fluid forces acting on a square prism using a planar jet
Akansu, Yahya Erkan; Fırat, Erhan; Hacıalioğulları, Mustafa
This experimental study focused on the concurrent minimization of the mean and fluctuating forces acting on a square prism in crossflow by creating a continuous jet through a narrow spanwise slot in it. For this purpose, three different predetermined injection surfaces (i.e., front, top, and rear) were individually studied for the injection ratios (IR) of 0, 1, 1.5, 2, 2.5, and 3 at a Reynolds number (Re) of 8000. The results showed that the rear jet is the optimum injection surface. For the rear jet configuration, the optimum IR is 1.5 in terms of mean total drag coefficient reduction, 〈CDT〉. In this case, the reductions in the 〈CDT〉 and the level of root mean square (RMS) of fluctuating pressure coefficient (CP RMS) on the side surfaces are about 29.7% and 68%, respectively. However, the maximum reduction in the CP RMS level on the side surfaces occurred at IR = 2. In this case, the reductions in the 〈CDT〉 and the level of CP RMS on the side surfaces are about 27.5% and 88%, respectively. The underlying mechanism of force reduction was also demonstrated. Various flow patterns were identified with respect to IR at incidence angle (α) of 0°. It was also proved that, at relatively small angles of incidence, from α = 0° to 20°, the active flow control method is still effective in reducing 〈CDT〉 and in suppressing the fluctuating side forces, which is indicative of periodic vortex shedding from either side of the square prism.
AtıfScopus18WoS18OpenAlex18İncele - BildiriYalnız künye2017A heuristic approach for joint design of assembly and disassembly line balancing problem
Mete, Suleyman; Çil, Zeynel Abidin; Özceylan, Eren
Balancing assembly and disassembly on parallel line together will positively affect to remanufacture production systems. In this study, two lines, which is one for assembly and other for disassembly, are considered as parallel line configuration. Parallelization of lines helps decrease the need for workforce significantly. Therefore, we propose heuristic approach based on ant colony optimization (ACO) for solving the balancing parallel line with minimizing number of workstations.
AtıfScopus2OpenAlex3İncele - MakaleAçık Erişim2017Scopus SJRQ3New solitary wave solutions to the (2+1)-dimensional Calogero–Bogoyavlenskii–Schiff and the Kadomtsev–Petviashvili hierarchy equations
Baskonus, Haci Mehmet; Sulaiman, Tukur Abdulkadir; Bulut, Hasan
In this paper, with the help of Wolfram Mathematica 9 we employ the powerful sine-Gordon expansion method in investigating the solution structures of the two well known nonlinear evolution equations, namely; Calogero–Bogoyavlenskii–Schiff and Kadomtsev–Petviashvili hierarchy equations. We obtain new solutions with complex, hyperbolic and trigonometric function structures. All the obtained solutions in this paper verified their corresponding equations. We also plot the three- and two-dimensional graphics of all the obtained solutions in this paper by using the same program in Wolfram Mathematica 9. We finally submit a comprehensive conclusion.
AtıfScopus42WoS44OpenAlex56İncele - MakaleYalnız künye2017Scopus SJRQ2Cosmology via thermodynamics of polytropic gas
Askin, Muzaffer; Salti, Mustafa; Aydogdu, Oktay
We study cosmological scenarios of the polytropic gas (PG) dark matter-energy proposal in a Friedmann-Robertson-Walker (FRW) Universe. As a first step, we obtain an exact expression for the energy density of PG model by making use of the thermodynamics. Later, we investigate some cosmological quantities and perform neo-classical analyzes. Finally, we implement a connection between the PG and a homogenous minimally coupled scalar field by introducing its self-interacting potential.
AtıfScopus10WoS10OpenAlex13İncele - MakaleYalnız künye2017Scopus SJRQ3The examination of a variety of different ions added to the crown ether derivatives with high field NMR spectrometer
Aşkin, Muzaffer; Zengin, Bilgin; Korunur, Sibel; Kor, Harun; Köylü, M. Zafer
The current study involves the measurements of T1 relaxation time of complexes three different crown ethers (4-aminobenzo-15-Crown-5, 1-Aza-18-Crown-6, 1-Aza-15-Crown-5) and two different ions sodium perchlorate (NaClO4), lithium perchlorate (LiClO4) by a 400 MHz NMR spectrometer. The association constants (Ka) of the complexes were determined on the basis of the evaluation of these measurements using the Benesi-Hildebrand method that we have modified. These association constants were consistent with those obtained from 1H NMR titration technique. As a result, it can be speculated that binding constants could be measured using T1 relaxation time when chemical shifts are very small or cannot be observed.
AtıfScopus1WoS1OpenAlex1İncele - MakaleYalnız künye2017Scopus SJRQ1Mechanical and fracture characteristics of self-compacting concretes containing different percentage of plastic waste powder
Gesoglu, Mehmet; Güneyisi, Erhan; Hansu, Osman; Etli, Serkan; Alhassan, Mahammed
This study addresses the mechanical and fracture properties of self-compacting concretes (SCCs) containing plastic waste (PW) powder in varying amounts used as a cement replacement material. Partial amount of cement was replaced by PW powder at 5%, 10%, 15%, 20% and 25% by weight so as to design six SCC mixtures with a constant slump flow of 700 ± 30 mm, total binder content of 550 kg/m3 and water-to-binder (w/b) ratio of 0.35. Mechanical characteristics of SCCs were tested for compressive and splitting tensile strengths, net flexural strength as well as modulus of elasticity at 28 day. Moreover, failure characteristics of the concrete were monitored via three-point bending test on the notched beams. The findings indicated that mechanical properties of PVC powder modified SCCs decreased while the concretes became less brittle.
AtıfScopus125WoS96OpenAlex136İncele - MakaleYalnız künye2017Scopus SJRQ2Effect of temperature and nitrogen concentration on the growth and lipid content of Spirulina platensis and biodiesel production
Seyhaneyildiz Can, Safak; Koru, Edis; Cirik, Semra
In this study, Spirulina platensis (Cyanophyceae) was cultured at five mediums with different amounts of sodium nitrate and three different temperatures. The study was conducted at 1600 lx light intensity and a pH value of 9. The influences of nitrate amounts and temperature on biomass growth and lipid amount were studied during 20 days. The best biomass growth (1.039 ± 0.668 g L−1 dry weight and 0.780 ± 0.501 optical density) for S. platensis was obtained from the group with the temperature value of 35 °C and 2.5 g L−1 of sodium nitrate. The highest lipid production (4.70 ± 0.067% dry weight) was in the nitrate-free medium at 15 °C. The best results for biomass growth and lipid production were obtained from the group at 35 °C and 1.25 g L−1 of sodium nitrate (P < 0.05). At the end of the study, it was determined that algal biomass increased with increasing the nitrate amount but the produced lipid by the algae decreased. Intensive production was performed in accordance with the culture conditions of the most productive groups and biodiesel was obtained from the algae. The density, viscosity, and flash point of the biodiesel were calculated as 0.78, 4.67, and 107 °C, respectively.
AtıfScopus34WoS27OpenAlex35İncele - MakaleYalnız künye2017Scopus SJRQ3Biochemical impacts of the textile dyes Remazol Brillant Blue R and Congo Red on the crayfish Astacus leptodactylus (Decapoda, Astacidae)
Aksu, Onder; Yildirim, Nuran Cikcikoglu; Danabas, Durali; Yildirim, Numan
In this study, we determined the effects of the textile dyes Remazol Brillant Blue R (RBBR) and Congo Red (CR) on the enzymatic activities of Glutathione S-Transferase (GST), cytochrome P450 (CYP1A1) and Lactate dehydrogenase (LDH), in hepatopancreas of Astacus leptodactylus. The crayfishes were exposed to 0.5, 1.0, and 2.0 mg/l of RBBR or CR, for 24 and 48 h. The recorded GST activity clearly increased after 24 or 48 h exposure to CR, compared to a control group (p<0.05), but the changes of GST activity depending on time and dose were not statistically significant in the RRBR group (p<0.05). The activity of CYP1A1 generally decreased, but LDH activity increased in the groups exposed to different doses of CR and RBBR, when compared to their control groups. Detoxification enzymes (as GST, and CYP1A1) and metabolic enzymes (as LDH) can be proven to make useful markers for further evaluating the physiological effects of CR and RBBR on crayfish.
AtıfScopus21WoS19OpenAlex23İncele - MakaleYalnız künye2017Scopus SJRQ3Developments in transfer hydrogenations of aromatic ketones catalyzed by boron compounds
Pasa, Salih; Gürler, Nedim; Temel, Hamdi; Rafikova, Khadichakhan; Aydemir, Murat
Boron complexes BL1 and BL2 were prepared from O-donor ligands, 2,2′-(1E,1′E)-(ethane-1,2-diylbis(azan-1-yl-1-ylidene))bis(methane-1-yl-1-ylidene)diphenol (L1) and 2,2′-(propane-1,3-diylbis(azan-1-yl-1-ylidene))bis(methane-1-yl-1-ylidene)diphenol (L2). The complexes were fully characterized by 1H and 13C NMR, LC-MS/MS, TGA/DTA, UV-Vis, elemental analysis, SEM, and FTIR. The transfer hydrogenation of acetophenone derivatives was investigated by the boron complexes in the presence of isoPrOH, as the hydrogen source, under basic condition with NaOH. The results showed that the boron complexes were promising catalytic precursors for transfer hydrogenation of aromatic ketones in 0.1 M isoPrOH solution (up to 99%). Both steric and electronic factors of this class of molecules had a significant impact on the catalytic properties.
AtıfScopus4İncele - MakaleYalnız künye2017Scopus SJRQ1A cause and effect relationship model for location of temporary shelters in disaster operations management
Celik, Erkan
The aim of the location of temporary shelter directly is to focus on helping the sufferers and injured people on disaster areas during and after a disaster. Facility location (location of temporary shelters) decisions play a critical role and affect directly performance of relief operations in disaster operations management (DOM). In this paper, a proactive decision-making tool by integrating decision-making trail and evaluation laboratory (DEMATEL) method with interval type-2 fuzzy sets (IT2FSs) is proposed to locate of temporary location in DOM. While DEMATEL method enables to analyse cause and effect relationship in decision-making process, the IT2FSs overcome ambiguity and vagueness of linguistic assessment of decision-makers through the DEMATEL. 14 different criteria for location of temporary shelters are considered by 9 disaster operation managers for evaluating the cause and effect factors. Beside the theoretical contribution of the proposed method, it provides practical benefits to disaster operation managers to perceive cause and effect relationship on location of temporary shelters.
AtıfScopus38WoS29OpenAlex41İncele - MakaleYalnız künye2017Scopus SJRQ1The effect of Zirconia/Yttria/Silver substitutions on mechanostructure and cell viability of the synthesized bioceramic bone grafts
Aksakal, Bunyamin; Demirel, Mehtap
Hydroxyapatite (HA) based biografts were synthesized by substitution of Zirconia (Zr), Yttria (Y2O3) and Silver (Ag) using the sol-gel method. Fabricated bone grafts (H40ZrYt and H50Yt10) were compared with a control biograft. The effects of Zr and Y2O3 and Ag additions on the morphological, mechanical and cell viability of the synthesized biografts were analyzed. The biografts were characterized by X-ray Diffractometer (XRD) and Scanning Electron Microscope (SEM). All biografts were then embedded into the drilled holes (D=3.2 mm) in rabbit femurs. The rabbits were then sacrificed after twelve weeks. Three-point bending (3-PB) tests were conducted on defected and grafted regions. Flexural strength values were found to be 347, 149 and 180 MPa, for the H40ZrYt, H50Yt10 and the control/commercial graft, respectively. Cell viability results indicated that the percentage viability ratios slightly increased after the substitution of Ag into the H50Yt10 biograft at 0.1 and 0.3 µg/ml concentrations and into the H40ZrYt biograft at a 0.1 µg/ml concentration. Although the cell viability was a bit lower in the H50Yt10 graft, the H40ZrYt graft achieved better results compared to the counterpart grafts. Furthermore, the hardness of both of the novel fabricated grafts were found to be higher than the control/commercial graft, however, as the flexture strength of H40ZrYt was higher but H50Yt10 was lower than the control/commercial graft.
AtıfScopus11WoS10OpenAlex13İncele - MakaleYalnız künye2017Scopus SJRQ2The effect and characterization of newly synthesized SrBr2 reinforced bone grafts on structure and cell viability
Demirel, Mehtap; Aksakal, Bünyamin; Kaya, Ali İhsan
Abstract: In this study, a highly durable SrBr2 compound was added to Ca(NO3)2·4H2O, KOH, NaNO3, P2O5, and urea (CO(NH2)2) compounds at different ratios (wt 10–30%); biografts were synthesized in different compositions using the sol gel method They were characterized using X-ray diffraction, Fourier transform infrared spectrometer, scanning electron microscope, and mechanical tests e.g. hardness and compression. Structural, mechanical properties and cell viabilities of the synthesized biografts were comparatively examined. Fourier transform infrared spectrometer and X-ray diffraction analysis results showed that, including SrBr2, hydroxyapatite had formed in the biografts. Also, hardness and compression tests revealed that compressive stress and hardness values of the grafts increased as the amount of SrBr2 increased. The cell viability ratios also enhanced with the amount of SrBr2 increased in the synthesized biografts. Graphical Abstract: [InlineMediaObject not available: see fulltext.]
AtıfScopus2WoS2OpenAlex3İncele - MakaleAçık Erişim2017Scopus SJRQ2A new bryophyte community and three new records for the epiphytic bryophyte vegetation of Turkey
Alataş, Mevlüt; Uyar, Güray
Based on 38 relevés, the Lewinskyetum affinis ass. nov. (Ulotion crispae alliance) was described and characterized as a new epiphytic association from the Abant Mountains (Northwest Turkey). To the best of our knowledge, this is the first report about three epiphytic bryophyte associations, namely Dicranetum taurici, Pterigynandretum filiformis, and Orthotricho straminei–Pterigynandretum filiformis, in Turkey. In addition, multivariate analysis techniques such as two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis (DECORANA) were used to examine epiphytic bryophyte communities for cluster analysis and ordination analysis, respectively.
AtıfScopus7WoS5OpenAlex4İncele - MakaleAçık Erişim2017Scopus SJRQ2New solitary and optical wave structures to the (1 + 1)-dimensional combined KdV–mKdV equation
Bulut, Hasan; Sulaiman, Tukur A.; Baskonus, Haci Mehmet; Sandulyak, Anna A.
In this article, we employ the sine-Gordon expansion method to construct a new solitary and optical wave structures to the (1 + 1)-dimensional combined KdV–mKdV equation. Sine-Gordon expansion method is developed based on the travelling wave transformation u(x, y) = U(ξ), ξ = μ(x − ct) and the sine-Gordon equation uxx − utt = m2 sin(u). We find the travelling wave solutions to (1 + 1)-dimensional combined KdV–mKdV equation in the form of complex, hyperbolic, trigonometric and rational function. Our results show that all the travelling wave solutions we obtain are solitary and optical wave structures solutions. All the computations and graphics plot in this article are carried out with the help of Wolfram Mathematica 9.
AtıfScopus44OpenAlex53İncele